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I and Js ratings
Quality on a good day: 2.0
Consistency of Surf: 3.0
Difficulty Level: 3.0
Crowds: 4.0

Overall: 3.0

See all 18 ratings

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Surf Report Feed

I and Js Swell Statistics, November: All Swell – Any Wind

This chart shows the range of swells directed at I and Js through an average November and is based upon 2867 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the optimum grid node based on what we know about I and Js, and at I and Js the best grid node is 35 km away (22 miles).

The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened only 23% of the time. Green and yellow illustrate increasing swell sizes and red shows the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell happens.

The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was SW, whereas the the prevailing wind blows from the SSW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from I and Js and away from the coast. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at I and Js, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause clean enough to surf waves at I and Js run for about 77% of the time.

IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.